Biology (11th Edition)

Chapter 4 - Cell Structure - Review Questions - Synthesize: 2

Answer

If mitochondria and chloroplasts are descended from once-freeliving prokaryote cells, they should have at least some properties unique to prokaryotes: protein-polysaccharide cell wall remnants, prokaryote-type ribosomes, and their own circular chromosome. They should also have more than one membrane as part of their structure as a remnant of the membrane which surrounded them when they were endocytosed. Mitochondria and chloroplasts have most of these features, especially the circular chromosome and bacterial ribosomes.

Work Step by Step

This question is one of the least well matched to the text. Basically, all of the unique features listed in table 4.3 can be found in some mitochondria or chloroplasts. This is even true for bacterial-type cell wall material, though it is the hardest of the unique features to find.